Effect Of Organoclay Modification On The Mechanical, Morphology, And Thermal Properties Of Injection Molded Polyamide 6/Polypropylene/Montmorillonite Nanocomposites.

Polyamide 6/polypropylene (PA6/PP = 70/30 parts) blends containing 4 phr (parts per hundred resin) of organophilic montmorillonite (OMMT) were prepared by melt compounding using co-rotating twin-screw extruder followed by injection molding

Valley spin polarization by using the extraordinary Rashba effect on silicon

The addition of the valley degree of freedom to a two-dimensional spin-polarized electronic system provides the opportunity to multiply the functionality of next-generation devices. So far, however, such devices have not been realized due to the difficulty to polarize the valleys, which is an indispensable step to activate this degree of freedom. Here we show the formation of 100% spin-polarized valleys by a simple and easy way using the Rashba effect on a system with C-3 symmetry. This polarization, which is much higher than those in ordinary Rashba systems, results in the valleys acting as filters that can suppress the backscattering of spin-charge. The present system is formed on a silicon substrate, and therefore opens a new avenue towards the realization of silicon spintronic devices with high efficiency.X114334Nsciescopu

Search for Dark Photon Dark Matter in the Mass Range 74-110 μeV with a Cryogenic Millimeter-Wave Receiver

ミリ波を用いたダークマター探索手法を確立. 京都大学プレスリリース. 2023-03-07.Thinking big and dark by starting small and light: Millimeter-wave technologies assist in examining 'light' dark matter. 京都大学プレスリリース. 2023-03-23.We search for the dark photon dark matter (DPDM) using a cryogenic millimeter-wave receiver. DPDM has a kinetic coupling with electromagnetic fields with a coupling constant of χ and is converted into ordinary photons at the surface of a metal plate. We search for signal of this conversion in the frequency range 18-26.5 GHz, which corresponds to the mass range 74-110 μeV/c². We observed no significant signal excess, allowing us to set an upper bound of χ<(0.3-2.0)×10⁻¹⁰ at 95% confidence level. This is the most stringent constraint to date and tighter than cosmological constraints. Improvements from previous studies are obtained by employing a cryogenic optical path and a fast spectrometer

Index Finger of a Human-Like Robotic Hand Using Thin Soft Muscles

The application of solar drying (SD) and heat pump-assisted solar drying (HPSD) on the retention of flavonoid components, total color changes, and water activity of Clinacanthus nutans Lindau leaves were investigated. Analysis of data shows significantly higher extractable yield and flavonoid (orientin and vitexin) percentage during the drying with HPSD. The same drying technique also revealed optimum color values and low water activity. Thin-layer models fitted to the experimental data show that Hii and Law model is suitable for SD, while logarithmic model is able to give a good fit to HPSD

Preparation and Deposition of Pr?Fe?B Permanent-Magnet Powder Using Pulsed Laser

We have already prepared a thin permanent magnet with the thickness of sub-millimeter by obtaining magnet powders using a pulsed laser deposition (PLD) method. In the article, the PLD followed by a flash annealing enabled us to deposit isotropic Pr-Fe-B magnet powders with coercivity (H-{\mathrm {cj}})> 1000 kA/m on a stainless thin shaft applicable to a miniaturized motor. Observation on the surface of Pr-Fe-B magnets and evaluation on the mechanical behavior were carried out. Since the surface of a Pr-Fe-B magnet was coated by a Pr oxide through an annealing process, their magnetic properties did not degrade after one year. We also confirmed that the Pr-Fe-B magnet has the possibility to be applied to a micro-magnetization process. It was clarified that the powder technology using the PLD is useful to propose a thin magnet applicable to a next-generation small motor

PLD-fabricated Pr-Fe-B thick film magnets applied to small motors

Although a conventional isotropic Nd-Fe-B bonded magnet (coercivity: 800 kA/m, thickness: 350 μm) has been widely used for a miniaturized motor, deposition of a thick film magnet without resin directly on a small shaft enables us to advance the further reduction of the motor. When obtaining the film magnet on the shaft, we carried out fundamental experiments using a stainless plate. Namely, we investigated the mechanical characteristic such as adhesion together with magnetic properties of PLD (Pulsed Laser Deposition)-made films as a function of Pr content. It was found that Pr-Fe-B films with Pr content above 15 at. % tended to peel from the plates after the deposition. We suppose that the result is attributed to the different linear expansion coefficient between a stainless (10.3×10-6 K-1) and Pr element (6.7×10-6 K-1). On the other hand, an increase in Pr contents of the samples enabled us to enhance coercivity compared with that of a conventional Nd-Fe-B bonded magnet. In the study, we prepared a 250 μm-thick Pr-Fe-B film magnet with the coercivity (Hcj) of approximately 1250 kA/m on a thin stainless shaft applicable to a small motor by the PLD

Neural development features: Spatio-temporal development of the Caenorhabditis elegans neuronal network

The nematode Caenorhabditis elegans, with information on neural connectivity, three-dimensional position and cell linage provides a unique system for understanding the development of neural networks. Although C. elegans has been widely studied in the past, we present the first statistical study from a developmental perspective, with findings that raise interesting suggestions on the establishment of long-distance connections and network hubs. Here, we analyze the neuro-development for temporal and spatial features, using birth times of neurons and their three-dimensional positions. Comparisons of growth in C. elegans with random spatial network growth highlight two findings relevant to neural network development. First, most neurons which are linked by long-distance connections are born around the same time and early on, suggesting the possibility of early contact or interaction between connected neurons during development. Second, early-born neurons are more highly connected (tendency to form hubs) than later born neurons. This indicates that the longer time frame available to them might underlie high connectivity. Both outcomes are not observed for random connection formation. The study finds that around one-third of electrically coupled long-range connections are late forming, raising the question of what mechanisms are involved in ensuring their accuracy, particularly in light of the extremely invariant connectivity observed in C. elegans. In conclusion, the sequence of neural network development highlights the possibility of early contact or interaction in securing long-distance and high-degree connectivity